Crawl space liner for the dirt floor or closed-cell spray foam?
I live in upstate NY and I have a 4 1/2′ high crawl space under my house with a dirt floor. I was told to insulate the walls with 3″ of closed spray foam and use a crawl space liner on the floor. Another contractor said I could use 2″ of closed spray foam on the walls and floor. Yet, another said 3″ should be used. Which is correct?
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